NAME

gmtcolors - Explanation of color codes in GMT

DESCRIPTION

Colors can be specified in GMT as arguments to commands, generally as
part of the -G or -W options to select polygon fill or outline pen.
Colors are also used in color pallette tables (cpt files) that help
convert numerical values to colors.
GMT allows several ways to represent a color:
Colorname
Specify one of the named colors below. All names are case-
insensitive.
R/G/B Specify Red, Green, and Blue levels. Each value is separated by
a slash and is in the range from 0 (dark) to 255 (light). This
representation is used to color monitors.
#RRGGBB
Specify Red, Green, and Blue levels in the way that it is done
in HTML. Use two characters for each color channel, ranging from
00 (dark) to FF (light). Upper and lower case are allowed.
Graylevel
For shades of gray, R = G = B, and only one number needs to be
used. This representation is popular with black and white
printers.
H-S-V Specify Hue in the range 0 to 360 (degrees), S saturation
between 0 (not saturated) and 1 (fully saturated), and value V
between 0 (dark) and 1 (light). Number are separated by hyphens.
This representation can be helpful when hue varies a lot.
C/M/Y/K
Specify Cyan, Magenta, Yellow, and blacK. Each number is in the
range from 0 (no paint) to 1 (maximum paint). This
representation is used by most color printers.